A synopsis on the effects of anthropogenic greenhouse gases emissions from power generation and energy consumption

Despite the looming difficult energy context in the majority of countries in the world, global change in environmental dignity resulting from power generation and energy consumption scenario is rapidly becoming a globally disturbing phenomenon. Stakeholders and environmental activists alike have been clamouring for adoption of reduction procedures using sustainable means because ignominious environmental practices have associated disastrous consequences. Increasing essential strategies are needed to fortify the pursuit for the reduction in the emissions from power generation and energy consumption. Therefore, this article presents an overview of the effects of anthropogenic energy generation and consumption practices capable of ejecting emissions of greenhouse gases into the atmosphere. It also endeavors to identify some greenhouse gas emission reduction and control measures

Evaluation of 11kv XLPE Cable

Underground power cables constitute a bulk part of power systems network. Most of these power system equipments have been in service for decades, thus making their insulation liable to deterioration (ageing) as a result of operational and environmental stresses. For the past decades, the Recovery Voltage Method (RVM) has been widely used to evaluate ageing in oil-paper insulated cables. This work presents the evaluation of ageing in 11kV XLPE cable using the RVM. Statistical Analysis was employed to predict the progress of ageing. Accelerated ageing using AC and impulse voltages was performed on new XLPE cable samples. Within the period of ageing, the state of insulation was investigated and assessed using the RVM. Regression Analysis was used to predict the progress of ageing in cables, with the CTC (central time constant) being the response variable. However due to technical problems encountered in the course of this study, synthetic data were used to model the regression equation. The result of the diagnosis using the RVM showed that the aged XLPE cables had higher values of Urmax (maximum return voltage) than the unaged ones, indicating the samples have undergone thermal ageing. An R2 of 0.981 was obtained from the regression equation, implying that the predicted values of the CTC were 98.1% close to the observed values. The RVM technique, which was initially proposed for diagnosis of oil-paper insulation systems, was found to be able to detect ageing in XLPE cables, and thus insulation diagnosis using this technique could be extended to extruded-insulated cable systems. The Regression Analysis, a tool for forecasting and prediction, can be used to predict the progress of insulation deterioration and agein

Odd harmonics and third to fifth harmonic ratios of leakage currents as diagnostic tools to study the ageing of glass insulators

This paper reports an investigation into the leakage current harmonic components of 45 units of glass insulator samples. The insulator units comprise 5 groups of insulators: new insulators and naturally field-aged insulators with different ageing periods->30, 20, 15, and <10 years from a 132 kV transmission line. Experiments were conducted at different electrical stresses (0.17, 0.24, and 0.34 kV/cm) and salt-fog conductivities (900 and 1500 µS/cm). The results suggest that the insulator samples¿ leakage current (LC) waveform and the total harmonic distortion (THD) correspond well with degree of ageing. Fast Fourier Transform (FFT) analysis performed on the stored waveforms showed a strong correlation between the ratio of the third to fifth harmonic amplitudes with the degree of ageing and in-service period of the naturally field-aged insulators. Furthermore, this investigation revealed a pattern between the groups of insulator samples in respect to their ageing. These findings were further validated with traditional Dielectric Dissipation Factor tests carried out on the insulators, and the results also correlated well with the samples¿ degree of ageing as well as service period. In addition, neural networks were trained to recognize the insulator samples¿ degree of ageing. This study found that, alternative to the diagnosis of insulator ageing through the measurement of loss angles or tangent delta, LC harmonics can be used as diagnostic tools and for the on-line monitoring of in-service aged transmission line ceramic glass insulators based on odd harmonics and third to fifth harmonic ratios

Information and communication technology for control and management in power systems smart grid

Architectures of modern electric power sector are fast becoming smarter in their mode of operations. Smart grid (SG) operations have potential capability to cover all the areas of generation, transmission and distribution of electrical energy. With the integration of computer technology, information and communication management in present day, grid system architecture is designed such that it is possible to solve many problems related to energy demand, supply and management constraints. As a promising technology, it is envisaged that SG will help in troubleshooting some of the present challenges such as cost of energy reduction, reliability monitoring and system stability improvement taken the advantages presented by the evolution of digital technologies. An overview of information and communication control and management in electricity smart grid system using wireless and other advanced electronic-based technologies is presented in this paper. The concept of smart grid as it is different from the existing power system utility architecture and its logical advancement presented for effective system monitoring, optimization and management functions are also introduced. In addition, different types of energy management smart grid communication systems are also discussed. In conclusions, some critical issues concerning the effective realization of the full intelligent nature of smart grid systems are discussed and areas for future work and further research suggeste

Sustainable potential of bioenergy resources for distributed power generation development in Nigeria

Rising concerns about global energy security and climate change due to emissions of noxious gases resulting from the combustion of fossil fuels have strongly renewed interest in renewable energy development. These concerns have also coordinated a reaction towards the global focus on a clean development mechanism, which is a basic strategy endorsed in the framework of the Kyoto Protocol. The use of biomass for the sustainable distributed generation of power offers immense hope to rural dwellers, who have limited access to electricity from centralized grid systems. Like other renewable sources of energy, biomass distributed-generation systems will play a critical role in the future of electrical power demand outlooks and energy generation planning. This article presents the wide-ranging potential of bioenergy resources in Nigeria for bioelectric power generation. It explicates the poor energy situation of the country and highlights different categories of biomass that can be exploited to tackle the energy deficiency in many rural communities. The study concludes with a discussion on the significance of distributed-generation electricity using bioenergy resources for rural energy supply, including brief discussions on the technologies for bioelectric power utilization

Electrical treeing in high voltage insulations: a review on nanocomposite insulating materials and their processing techniques

Electrical treeing is one of the major causes of breakdown/failure of polymeric insulations. Nanocomposite materials play an important role in preventing insulation breakdown due to the presence of nanoparticles. Nanoparticles act as charge trapping sites and physical barriers to electrical treeing thereby hindering their growth. This study presents a review on electrical treeing studies on nanocomposite materials and processing techniques employed to mitigate insulation failure due to electrical treeing. Various polymers combined with different nanofillers as well as the most common processing techniques are also reviewed. Emerging trends on nanomaterial surface modification to improve electrical treeing resistance are also discussed

Statistical study on tree inception voltage of silicone rubber and epoxy resin

Weibull distribution has been used widely by many researches around the world especially in the analysis of high voltage experimental data. Unfortunately, most of the experimental data analysis was not following the accurate statistical technique. Thus in this paper, a statistical study on the tree inception voltage of silicone rubber and epoxy resin is presented. The tree inception voltage of silicone rubber and epoxy resin was measured via camera-equipped online monitoring system. The leaf-like specimen was used as test sample. The experiment was performed based on IEC 1072:1991 Methods of Test for Evaluating the Resistance of Insulating Materials against the Initiation of Electrical Trees". The obtained results were analysed statistically by using fitting method. Anderson-Darling goodness-of-fit test was performed in order to obtain the best fitting distribution. Comparison exercise was made between the fitted distribution and Weibull distribution. Based on Anderson-Darling tests, the tree inception voltage of silicone rubber and epoxy resin was best fitted with Johnson SB distribution. Based on this fitted distribution, the value of tree inception voltage for silicone rubber and epoxy resin was calculated and equalled to 3.1529 kV and 4.6528 kV respectively. Thus, it was found that, the fitting method by means of Anderson-Darling goodness-of-fit test was successful to recognize the best fitted distribution for the value of tree inception voltage for silicone rubber and epoxy resin. © 2011 IEEE

Organo-montmorillonite as an electrical treeing retardant for polymeric insulating materials

This paper presents investigation on the propagation of electrical treeing in silicone rubber samples filled with Montmorillonite (MMT) and Organo-montmorillonite (OMMT) nanoclays as fillers for electrical tree inihibition. Treeing experiments were conducted by applying ac voltage with increasing rate of 0.5 kV per second at power frequency on pure silicone rubber, silicone rubber filled with 1% MMT and silicone rubber filled with 1% OMMT samples respectively and treeing propagation length and inception voltage within 30 minutes aging period were observed. Result from this study showed that the silicone rubber/OMMT sample exhibited the shortest tree length as well as highest tree inception voltage followed by the silicone/MMT sample with the pure silicone rubber having the least electrical performance. This finding suggests the OMMT can be used a filler in polymeric insulating materials for electrical tree inhibition